Door operator



fj'UNITED. 'STATES PATENT .OFFICE I y e v, 2,298,542

DOOR OPERATOR Manufacturing Company, Stamford, Conn., a=

corporation of Connecticut Application April 9, 1940, Serial No. 328,622

17 Claims.

This invention relates to a door, opening and closing mechanism formingan improvement of the door opening and closing mechanism shown inYourapplication Serial No. 188,512, filed in the United States Patent Ofliceon February 3, 1938.

As in the said application, the important feature of: our invention isthe utilization of a commercial form of door closer such as is shown inthe Potter Patent No. 1,926,554 and in the Norton Patent No. 1,152,339,to open the door to which the closer is attached through the applicationof nuid pressure to the checking piston. The application of this fluidpressure will reverse the usual action of the closer and cause it toopen the door through the same means as are normally used for closingthe door. It is a further feature of our invention that should the fluidpressure source cease to function, the door maybe opened and closed inthe same manner as though it were controlled by the usual type ofcommercial door closer.

The several features so far discussed by us are inherent in theconstruction shown in our application supra, vthe invention in thisapplication being a modification whereby we simplify the valve andcontrol mechanism of the door closer and opener so that it will betterperform its operations.

We shall now describe the drawing wherein our invention is showngenerally in a diagrammatic form. We have preferred to show theinvention in diagrammatic form because the door closer is well known inthe art, while the pumping mechanism is of a type which anyone skilledin the art couldassemble quite readily. In addition, both the doorcloser and the pumping mechanism are more particularly described in ourearlier application. We do show in considerable detail the actualstructure of a valve body which forms an important part of ourinvention.

Referring nowmore particularly to the drawing, Fig. 1 is a diagrammaticview of our door closing and opening mechanism applied to a door. Fig. 2is a diagrammatic view of the parts of Fig. 1 with certain of thoseparts enlarged to more accurately show their operation. Fig. 3 is a viewof the valve body shown in Fig. 2, but with certain parts thereof in adifferent position. Fig. 4 is a -section along lines 4-4 of Fig. 3.

Referring now more particularly to the drawing, reference numeral IIIdesignates a door which is mounted for opening and closing movementrelatively to a frame'l I. A door closer I2 of ,the

type disclosed in our earlier application and 55 shown more particularlyin the Norton and Potter patents supra, is secured through a bracket I3to the door frame. It is connected through an arm I4, pivoted at I5 toan arm Ii, to the door II, all in a manner which is well known in theart. As a matter of fact, the door closer I2 may be secured to the door,and be connected by the arms I4 and I6 to the door frame. 'I'hoseskilled in the art will fully appreciate the several different types ofinstallations possible.

The door closer I2 is connected through the intermediary of a valve bodydesignated by the reference letter V, to a source of fluid pressure,designated generally by the reference letter P, it being understood thatwhen fluid under pressure is transmitted from the fluid pressure sourceP through the valve body V to the door closer I2, the door is openedthrough a reversal of the operation of the door closer.

The operation of the fluid pressure source P is controlled by suitablephoto-electric equipment, designated by reference letters L and L'.Those skilled in the art will appreciate that with the provision ofsuitable electric circuits, shown in our earlier application, theinterception of the light beams B and B' will bring about the actuationof the fluid pressure source P to force fluid under pressure into thedoor closer to open the door.

We shall now refer to Figs. 2, 3 and 4, where our invention is shown ingreater detail and will be more readily understood. In Fig. 2, the doorcloser I2 is shown equipped with brackets II and I8 whereby it isreadily secured to the main bracket I3. A checking piston I5 equippedwith heads 20 and 2l slides in the cylinder 22 of the door closer, andhas a. rack portion 23 in engagement with a pinion 24 secured to themain shaft 25 of the closer. The shaft 25 is urged toward closedposition by the usual spring 25, it being understood that upon openingof the door, the arms I l and I6 act to wind the spring through theshaft 25 and to move the piston I9 to its extreme left hand position,which movement is substantially unopposed, since the liquid of the doorcloser will flow in the cylinder 22 from one side of the piston to theother through valve passages 21 and 29, and past the ball valve 2lcarried by the piston head 20.

In the usual type of door closer, such as shown in the Potter and Nortonpatents, the right hand end of the closer is equipped as is the lefthand end shown in Fig. 2; that is. there are present the passages 2l and29, and a -valve adjusting screw 30.' Our door closer is modied by theof the cylinder 22.

It is apparent, therefore, that unless means are provided for allowingthe escape of fluid between the piston head 26 and the cap 3l at thehigh pressure end of the cylinder 22, the door will be incapable ofclosing under the iniiuence of the closer spring 26. We shall nowdescribe the means whereby the said iluid may be moved by the pistonhead 26 relatively to the pressure end of the cylinder 22 to the lowpressure end of the cylinder incidental to the closing oi' the door. In

- this same connection, we shall describe the means whereby the doorcloser action 'is reversed by the application of fluid against thepiston head 26.

In Fig. 2, we have shown the source of fluid pressure P as including amotor M, which through a suitable coupling 32 drives a pump 33, `whosesupply line 34 extends from a tank 35. The pressure line of the pump isdesignated by reference numeral 36 and extends through a nipple 31 intothe valve body V. Formed in this valve body is a passage 38communicating with a further passage 39 which is in furthercommunication 'with a passage 46. The passage 46 in turn leads to anipple 4I which is connected to a pipe 42. 'I'he pipe 42 in turn leadsthrough a nipple 43 into the cap 3l, forming the pressure end oi.' thedoor closer cylinder 22. In considering our invention, it will be wellto note that the pipe 36, nipple 31, passages 38, 39, 46, nipple 4I,pipe 42, and nipple 43, form what we call the pressure line leading fromthe pump to the door closer.

A nipple 44 is secured to the door closer, as shown in Fig. 2, on thelow pressure side of the door closer piston, and is connected throughthe pipe 45 and nipple 46 with the passage 41 of the valve body V. Inturn, the passage 41 is connected through nipple 48 and pipe 4'6 back tothe tank 35 of the fluid pressure source P. Nipple 44, pipe 45, nipple46, passage 41, nipple 48 and pipe 49 form what we term the exhaust`line leading from the low pressure side of the door closer pistonchamber to the iluid pressure source P.

A relief line 34a extends from the pressure line to the pressure reliefvalve 35a, so that the pressur@ of the fluid made available to thecloser I2 may be controlled.

Mounted in the passage 38 is a piston 56 spring pressed by a spring Iagainst a pin 52 so as to shut olf all communication between passages 36and 36 of the valve body. It will `be noted that the spring 5I issupported and maintained in position by a pin 53 forming part of a screwplug 54 which closes the upper end of the passage 38. It will further benoted that leading from the passage 46 is a Toy-,pass passage 55 whichextends into the passage 38 and through said passage 38 communicateswith a further by-pass passage 55a released, it will be closed by thespring." The piston head 26 of piston I3 will move against the fluid andforce it out of the pressure end of the chamber 22 through the pressureline into the leading to the passage 41. An adjusting valve for varyingthe size of the passage 55 is designated by reference numeral 56.Functionally, we consider the passages 55 and 55a as forming with thepassages 46 and 41, a by-pass passage around the fluid pressure sourceP.

In the position of the parts in Fig. 2, the piston 56 is spring pressedagainst the pin 52 so that while it shuts of! communication betweenpassages 38 and 39, it opens and allows full communication from thepressure line to the exhaust line through the by-pass passages 55 and56a.. Because of this relation ofthe parts, should the door have beenopened manually and the spring wound as already described, if the doorbe then valve body V, thence through by-pass passages 55 and 55a to theexhaust line and back through the nipple 44 into the low pressure end ofthe closer. The speed of movement of the fluid will of course dependupon the setting of the valve 56, and thereby the speed of closing ofthe door may be readily determined and adiusted.

We believe it will now be clear to those skilled in the art that thedoor Il may readily be opened manually with practically no resistance ofthe fluid, due to the fact that the fluid will flow freely past passage21 and past ball valve 28 in a manner well known in the art. It will -befurther appreciated that the door is closed in the usual way, but thatthe fluid instead of being forced through the usual valve passages suchas 21 and 23 under the control of a screw valve' 36, will be forcedinstead through the, by-pass passage of the valve body V as controlledby the adjusting valve 56.

Fig. 3 shows the position of the parts in the valve body when fluidunder pressure is applied from the fluid pressure source to the doorcloser through the intermediary of the valve body V. In that case, thecontrol piston 56 is moved against the pressure of spring 5I into anupper position in which it shuts oil the by-pass passage and opens upthe pressure line through opening up communication between the passages38 and 38. Pressure is then applied to the end of the piston head 26which moves to the left in Fig. 2 to open the door and to wind thespring 26.

Incidentally, it will be interesting to note that in the ilnal openingmovement of the door, the piston head 2| will shut oil passage 21, andthereafter, all uid between the piston head 2l and the end cap 58 mustescape through the passage 29 as controlled by the screwvalve 36. By aproper setting of the screw valve 36, the movement of the piston I8 maybe snubbed or checked so as to cushion the nal opening action of thedoor.

As soon as pressure in the pressure line is relieved by the shutting oliof the pressure from the fluid pressure source, the control valve piston56 will move back to the position of Fig. 2, and the piston I8 will movetoward the right in Fig. 2 under the influence of spring 26, causing thepiston head 26 to move toward the pressure end cap 2l of the cylinder.'I'his movement forces the liquid out through the pressure line andthrough the now open by-pass passages 55 and 56a past the adjustingvalve 5l and through the exhaust line back to the low pressure side ofthe door closer chamber 22, bringing the door into closed position. Itwill be appreciated that this closing movement of the door takes placeunder exactly the same conditions as when the door is opened manuallyand released for closing.

Referring to Fig. 4, we show the adjusting valve 56 and the manner inwhich it is set by rotation of the screw head 51, all as is wellunderstood by those skilled in the art.

While we have thusdescribed a particular detailed form in which ourinvention is preferably embodied, it will naturally be understood thatthose skilled in the art may embody our invention in other forms whilestill 'utilizing our contribution to the art.

We now4 claim: Y

l. In a combination of the class described. a

door closer having a cylinder. a piston movable in said cylinder, ailuid pressure source, a valve body, a pressure line leading fromsaid'fluld pressure source to said valve body and from said valve bodyto the high pressure end of said cylinder, an exhaust line leading fromthe low pressure end of said cylinder to the iluid pressure source, apressure e in said valve body forming a functional part of said pressureline, a by-pass passage in said valve body leading from the pressurepassage to the exhaust line, means movable incidentally to the ilow ofiluld under pressure from said iiuid pressure source to said pressurepassage for the flow of fluid therethrough into said cylinder, whereby'saidiluid acts against the piston to reverse the normal action of thedoor closer, said means moving to open said by-pass passage and to shutoil said pressure passage incidental to the stoppage ofthe flow of fluidunder pressure from said fluid pressure source, whereupon said pistonforces said iluid from the high pressure end of said cylinder throughsaid by-pass passage toward the low pressure end of said cylinder.

2. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a iluid pressure source, avalve body, a pressure line leading from said duid pressure source tosaid valve body and from said valve body to the high'pressure end ofsaid cylinder, an exhaust line leading from the low pressure end of saidcylinder to the fluid pressure source, a pressure passage in said valvebody forming a functional part of said pressure line, a by-pass passagein said valve body leading from the pressure passage to the exhaustline, a regulating valve for adjusting the effective size of saidpassage, a valve piston in said valve body movable upon flow of fluidunder pressure from said iluid pressure source to obstruct said by-passe while opening up said pressure passage for the ilow of fluidtherethrough into said cylinder. whereby said iluid acts against thedoor closer piston to reverse the normal action of the door closer, saidvalve piston moving to open said bypass passage and to shut oiI saidpressure passage incidental to the stoppage of the ilow of iluid underpressure from said fluid pressure source. whereupon said piston forcessaid iluid from the high pressure end of 4said cylinder through saidby-pass passage toward the low pressure end of said cylinder.

3. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a iluid pressure source, avalvek body, a pressure line leading from said fluid pressure source tosaid valve body and from said valve body to the high pressure end ofsaid cylinder, an exhaust line leading from the low pressure end of saidcylinder to said valve body and from said valve body to the fluidpressure source, a pressure passage in said valve body forming afunctional part of said pressure line, an exhaust passage in said valvebody forming a functional part of said exhaust line, a by-pass passagein said valve body leading from the pressure passage to the exhaustpassage, a regulating valve for adjusting the edective size of saidpassage, a valve piston in said valve body spring pressed into positionto shut od said pressure passage and movable upon ilow of iluid underpressure from said fluid pressure source to obstruct said by-passpassage while opening up said pressure passage for obstruct said by-passpassage while opening up cylinder, whereby to reverse the normal actionof the door closer, said valve piston moving into position to block`said pressure passage upon the stoppage of the ilow of duid underpressure from said. duid pressure source through into said while openingsaid by-pass passage, and means for moving the door closer piston toforce the fluid out of the high pressure end of the cylinder throughsaid pressure line and by-pass passage and through the exhaust line to`the low pressure end of the cylinder.

4. In a combination of the dass described, a

leading from said fluid pressure source to said leading from the theiluow of fluid therepressure source,

valve body and from said valve body to the high pressure end of saidcylinder, an exhaust line leading from the low der to said valve bodyand from said valve body to the iluid pressurel source, a pressurepassage in said valve body forming a functional part of said pressureline, an exhaust passage in said valve body forming a functional part ofsaid exhaust line, a by-pass passage in said valve body pressure passageto the exhaust passage, a regulating valve for adjusting theeffectivesize of said by-pass passage, a valve piston in said valve bodyspring pressed into position to shut oil said pressure passage andmovable upon ilow of iluid under pressure from said uid pressure sourceto obstruct said by-pass passage while opening said pressure passage forthe flow of fluid therethrough into said cylinder, whereby to reversethe normal action of the door closer to open the door, said valve pistonmoving into position to block said pressure passage upon the stoppage ofthe ilow of fluid under pressure from said iluid pressure source whileopening said by-pass passage, whereupon the said door closer will act toclose the door with the door closer piston forcing the iluid out of thehigh pressure end of the cylinder through said pressure line and by-passe and through the exhaust line to the low pressure end of the cylinder,and means whereby fluid flows freely from the low pressure side of thedoor closer piston to the high pressure side thereof to permit easymanual opening of the door to which the door closer is applied.

5. In a combination of the class described, a door closer having in saidcylinder, a spring adapted to close the door to which the closer issecured while said piston serves to slowdown the closing action, a iiuidpressure source, a prsure line connecting said tluid pressure sourcewith the pressure end of said cylinder, an exhaust line connecting thelow pressure end of said cylinder with the fluid pressure source, and aby-pass passage for said iluid pressure source leading from said highpressure line to said low pressure line whereby when said spring closesthe door, fluid is forced by said piston out of the pressure` end of thecylinder and through said by-pass passage toward the low pressure end ofsaid cylinder.

6. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowcheck valve in said piston to permit free passage of uid when the dooris opened manually, a fluid a pressure line connecting said pressure endof said cylina cylinder, a piston movable down the closing action, a

fluid pressure source with the pressure end of said cylinder, an exhaustline connecting the low pressure end of said cylinder with the nuidpressure source, a by-pass passage for said fluid pressure sourceleading from said high pressure line to said low pressure line, aregulating valve in said by-pass passage, means normally maintainingsaid by-pass passage open while maintaining closed said pressure line tosaid fluid pressure source, whereby said piston forces the fluid fromthe'pressure end of the cylinder through said bypass passage andregulating valve toward the low pressure end of the cylinder and inby-passing relation to said fluid pressure source during the closingmovement of the door by said spring.

'1. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowdown the closing action, a fluid pressure source, a pressure lineconnecting said fluid pressure source with the pressure end of saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, means for initiating theapplication of fluid from said fluid pressure source against said pistonto reverse the action of the closer and to open the door, a by-passpassage for said fluid pressure source leading from said high pressureline to said exhaust line, a regulating valve in said passage, meansnormally maintaining said bypass passage open while maintaining closedsaid pressure-line to said fluid pressure source, whereby said pistonforces the fluid from the Pressure end of the cylinder through saidby-pass passage and regulating valve toward the low pressure end of thecylinder during the closing movement of the door by said spring afterthe door has been opened by the application of fluid from said fluidpressure source against said piston, and means whereby fluid flowsfreely from the low pressure side of the door closer piston to the highpressure side thereof to permit easy manual opening of the door to whichthe door closer is applied.

8. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowdown the closing action, a'fluid pressure source, a pressure lineconnecting said fluid pressure source with the pressure end of I saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, a by-pass passage for saidfluid pressure source leading from said high pressure line to said lowpressure line, a regulating valve in said passage, a spring pressedvalve piston normally maintaining said by-pass passage open whilemaintaining closed said pressure line to said fluid pressure source,whereby said lines and passage will act to control the closing of thedoor through the forcing of fluid by the door closer piston from thepressure end of thev cylinder through said by-pass passage andregulating valve to the low pressure end of the cylinder, said valvepiston being movable upon the application of uid under pressure fromsaid uid pressure source to open the pressure line while shutting oifthe by-pass passage whereby fluid under pressure will be admitted tosaid cylinder against the door closer piston to reverse the normalaction of the door closer and to open the door.

9. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while piston serves to slow downthe closing action, l. fluid pressure source, a pressure line connectingsaid fluid pressure source with the pressure endA of said cylinder, anexhaust line connecting the low pressure end of said cylinder with thefluid pressure source, a by'pass passage for said fluid pressure sourceleading from said high pressure line to said low pressure line, aregulating valve in said passage, a spring pressed valve piston normallymaintaining said by-pass passage open while maintaining closed saidpressure line to 'said fluid pressure source, whereby said lines andpassage will act to control the closing of the door through the forcingof fluid from the pressure end of the cylinder through said by-pass eand regulating valve to the low pressure end of the cylinder, said valvepiston being movable upon the application of fluid under pressure fromsaid fluid pressure source to open the pressure line while shutting offthe by-pass passage wherebyfluid under pressure will be admitted to saidcylinder against said door closer piston to reverse the normal action ofthe door closer to openthe door, and means whereby iiuid flows freelyfrom the low pressure side of the door closer piston to the highpressure side thereof to permit easy manual opening of the door to whichthe door closer is applied.

l0. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowdown the closing action, a fluid pressure source, a pressure lineconnecting said ud pressure source with the pressure end of saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, a by-pass passage for saidfluid pressure source leading from said high pressure line to said lowpressure line, a regulating valve in said passage, means normally.maintaining said by-pass passage open while maintaining closed saidpressure line to said iluid pressure source, whereby said lines andpassage will act to control the closing of the door through the forcingof fluid from the pressure end of the cylinder through said by-passpassage and regulating valve to the low pressure end ofthe cylinder,said means being movable upon the application of fluid underpressurefrom said fluid pressure source to open the pressure line while shuttingolf the by-pass passage whereby fluid under pressure will be admitted tosaid cylinder against said door closer piston to reverse the normalaction of thedoor closer to open the door, and means whereby fluid flowsfreely from the low pressure side of the door closer piston to the highpressure side thereof to permit easy manual opening of the door to whichthe door closer is applied.

11. In a combination of the class described, a

Y door closer having a cylinder, a piston movable in said cylinder, aspring adapted to close the door to which the closer is secured whilesaid pis-` ton serves to slow down the closing action, a fluid pressuresource, a pressure line connecting said fluid pressure source with thepressure end of said cylinder, an exhaust line connecting the lowpressure end of said cylinder with the fluid pressure source, a by-passpassage for said fluid pressure source leading from said high pressureline to said low pressure line, a regulating valve in said passage, aspring pressed valve piston nor-v mally maintaining said by-pass passageopen while maintaining closed said presure line to said duid pressuresource, whereby said lines and passage will act to control the closingof the door through the forcing of iiuid from the pressure end of thecylinder through said by-pass passage and regulating valve to the lowpressure end of the cylinder, said valve piston being movable upon theapplication of iluid under pressure from said fluid pressure source toopen the pressureA line while shutting oil' the by-pass passage wherebyfluid under pressure will be admitted to said cylinder to reverse thenormal `action of the door closer to open the door, the said springpressed valve piston moving back to its saidnor mal position uponstoppage of the dow of fluid under pressure from said fluid pressuresource,

whereupon the said door closer will act to close the door with the doorcloser piston forcing the fluid out of the high pressure end of thecylinder through said pressure line and by-pass passage and through theexhaust line to the low pressure end of the cylinder.

12. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowdown the closing action, a uid pressure source, a pressure lineconnecting said fluid pressure source with the pressure end of saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, a lay-pass passage for saidiluid pressure source leading from said high pressure line to said lowpressure line, a regulating valve in said passage, a spring pressedvalve piston normally maintaining said lby-pass passage open whilemaintaining closed said pressure line to said iluid pressure source,whereby said lines and passage will a-ct to control the closing of thedoor through the forcing of fluid by the door closer piston from thepressure end of the cylinder through said by-pass passage and regulatingvalve to the low pressure end of the cylinder, said valve piston beingmovable upon the application of fluid under pressure from said fluidpressure source to open the pressure line while shutting oi! the by-passpassage whereby uid under pressure will be admitted to said cylinder toreverse the normal action of the door closer to open the door, the saidspring pressed valve piston moving back to its said normal position uponstoppage of the ilow of iluid under pressure from said uid pressuresource, whereupon the said door closer spring will close the door withthe door closer piston forcing the fluid out of the high pressure end ofthe cylinder through said pressure line and bypass passage and throughthe exhaust line to the low pressure end of the cylinder, and meanswhereby fluid ows freely from the low pressure side of the door closerpiston to the high pressure side thereof to permit easy manual openingof the door to which the door closer is applied.

13. In a combination of the class described, a door closer having acylinder formed with a high pressure end and a low pressureend, a pistonmovablein said cylinder from the high pressure end to the low pressureend during opening movement of thedoor to which the closer is attached,and then to the high pressure end as the door closes, a spring adapted.to close the' door to which the closer is secured while saidpistonserves to slow down the closing action, a uid pressure source, apressure line connecting said fluid pressure source with the pressureend of said cylinder, an exhaust line connecting the low pressure haustline, and means for directing the flow of fluid under the pressure ofthe piston from the pressure end of the cylinder through said bypasspassage and exhaust line to the low pressure end of the cylinder whensaid spring moves said door to closed position.

14. In a combination of the class described, a door closer having acylinder formed with a high pressure end and a low pressure end, apiston movable in said cylinder from the high pressure end to the lowpressure end during opening movement of the door to which the closer isattached, and then to the high pressure end as the door closes, a springadapted to close the door to which the closer is secured while saidpiston serves to slow down the closing action, a uuid pressure source, apressure line connecting said iiuid pressure source with the pressureend of said cylinder, 'an exhaust line connecting the low pressure endof said cylinder with the fluid pressure source. a by-pass passage forsaid fluid pressure source leading from said high pressure line to saidexhaust line, a regulating valve in said by-pass passage, and means fordirecting the flow of fluid under the pressure of the piston from thepressure end of the cylinder through said by-pass pmage and exhaust lineto the low pressure end of the cylinder when said spring moves said doorto closed position.

15. In a combination of the class described, a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said Ipiston serves toslow down the closing action, a fluid pressure source, a pressure lineconnecting said uid pressure source with the pressure end of saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, a by-pass passage for saidfluid pressure source leading from said high pressure line to said lowpressure line, a regulating valve in said passage, means normallymaintaining said whereby said lines and passage will act to control theclosing of the door through the forcing of fluid by the door closerpiston from the pressure end of the cylinder through said by-passpassage and regulating valve to the low pressure end of the cylinder,said means being movable upon the application of fluid under pressurefrom said iluid pressure source to open the pressure line while shuttingoff the by-pass passage whereby fluid under pressure will be admitted tosaid cylinder against the said piston to reverse the normal action ofthe door closer and to open the door.

16. In a combination of the class described', a door closer having acylinder, a piston movable in said cylinder, a spring adapted to closethe door to which the closer is secured while said piston serves to slowdown the closing action, a fluid pressure source, a pressure lineconnecting said fluid pressure source with the pressure end of saidcylinder, an exhaust line connecting the low pressure end of saidcylinder with the fluid pressure source, a by-pass passage for saidfluid pressure ingoithedoorthroughtheioreingoimxidbythedoorcloserpistontromthe pressureendofthe cylinder through said by-passpassage and regulating valve to the inder, said means being movable uponthe application o! iluid under pressure from 'saidiluid pressuresourcetoopenthepressurelinewhileshutting oi! the byfpass passage whereby nuidunder pressuremllbe admitt'edtnsaideylinderagainst' the said piston toreverse the normal actiun ot the dnor closer and to open they door, andmeans whereby iluid flows freely from the low pressuresideofthedoorcloserpiswntothehlhpres--suresidethereoi'tepermlteasymanualopening man low pressure end ot thecylthecioserissemredwhilesaidplstcnm slow down the closing aetlen. ailuid souree,apressurelineeonneetingsaidmiidpressuresoureewlththepressureend-otsaid der. anexhaustlineeonneeting'theluw'prelureendofsaideylinderwlththemlidpresnnesmnee.

Y @en said door, means for shutting said ivy-pase passage incidental tothe said application o! :lluid against saidpiston and for opening saidthereafter to permit the piston to tores from the pressure end of thecylinder said by-pass passage and exhaust line to pressure end of themoves said door to closed position.

s ROBERT BL POTTER.

' MAURICE D.' m11.

